Doing a quick search for Monday 4th June, if you want to travel by train from London Euston to Carlisle during peak commuting hours (for example a day return business trip) it will cost you in excess of £200 return and take 4h 26mins each way.
Carlisle to London Euston return will cost roughly £120 and take between 4h 30 and 3h 30 (if a fast service) each way.
Looking at a potential flight from CAX to SEN, well we know that you won't have to arrive early at CAX (maybe an hour prior to your departure time tops). Then a 1h 20mins flight roughly, plus 1h 20mins max from landing at SEN (getting through terminal and catching train to Liverpool Street). That would equal a total journey time from Carlisle to Central London of roughly 3h 40mins. If the price is right it could persuade some people. I think the hassle free nature of both airports must be emphasised. So in terms of time difference a flight would be competitive.
Last edited by tws123; 23rd Jan 2018 at 12:03.